Temporal variations of spontaneous plants colonizing in different type of planted vegetation-a case of Beijing Olympic Forest Park

Abstract

The planted vegetation in urban green spaces generally not only needs intensive maintaining practices but also has resulted in landscape homogeneity and biodiversity decrease. With the increasing ecological awareness, spontaneous plants which were seen as ‘weeds’ have gained attention for their variety of positive attributes. To provide an insight for designers to cooperate with them, we took Beijing Olympic Forest Park as the study area, and explored the temporal patterns of spontaneous plants in relation with planted vegetation. A total of 614 plots were selected from 123 sample sites using a 200-m grid placed over the park. Each plot was a 1 m × 1 m square, and was assigned one microhabitat type according to the type of planted vegetation. All plots were surveyed seven times during the growing season from March to November, 2015. A total of 128 spontaneous species were recorded, which belonged to 98 genera and 32 families. It was under-tree and unplanted plots contained the most species among all of the other microhabitats whereas lawn presented the lowest species number throughout the growing season. Significant differences were found among the microhabitats with respect to species richness and community diversity of spontaneous vegetation, with under-tree and lawn were dramatically lower compared to unplanted plots during the whole summer. In contrast, the most diverse communities were recorded at waterside unplanted plots. Moreover, community diversity and species niche width among different microhabitats were not stable because of the varying degrees of external interference in different seasons. Totally 21 distinct colours of spontaneous vegetation were identified during the survey season. Each season and microhabitat had its own dominant species and assemblages. The results of this research can provide a reference for the future design of sustainable and resilient urban vegetation that is both ecologically productive and aesthetically pleasing, and at last has substantial potential for a greater inherent stability in the face of global climate change.